What Are the Craze Lines?

Craze lines are superficial, vertical lines that appear in tooth enamel, usually as people age. They’re also referred to as hairline cracks or superficial cracks.

Craze lines may be translucent. They may also appear gray, yellow, or brown.

If you suddenly notice multiple craze lines on your front teeth, you may find them unsightly. However, craze lines are often hard to see and go completely unnoticed unless you look for them.

Craze lines can cause your teeth to stain more easily. For that reason, they may be more visible in people who use tobacco products or who drink coffee, tea, soda, or red wine.

What causes craze lines?

Craze lines have a number of causes, including plain old wear and tear.

Many years of chewing food and putting pressure on teeth eventually add up, causing craze lines to form. That’s why people often notice them as they approach middle or older age.

In addition to wear and tear, other causes of craze lines include:

• teeth grinding (bruxism)
• misaligned teeth (uneven bite)
• a long-term nail biting habit
• chewing on non-food items such as ice or hard objects
• injury or trauma to teeth

Craze lines vs. cracked teeth  

Craze lines are technically a minor type of cracked tooth. Unlike more severely cracked teeth, craze lines don’t usually worsen or cause symptoms.

In most instances, craze lines are solely a cosmetic concern and don’t require treatment to preserve the tooth.

An easy way to determine whether you have a craze line or a crack in your tooth is to check your symptoms. If you don’t have pain, swelling, or sensitivity, you most likely have a craze line and not a crack.

Can a craze line lead to a cracked tooth?

Craze lines are a normal and common occurrence. They don’t mean that your teeth are weak or prone to cracks.

They usually don’t worsen or lead to cracks. They may, however, make teeth more prone to cavities, though rarely on the front teeth.

This can be avoided by brushing your teeth, especially after having sugary foods or drinks, and employing good dental hygiene habits.

What are options to “fix” craze lines?

If you don’t like the look of craze lines, there are things you can do to lighten them at home, such as using whitening strips or whitening toothpaste.

Your dentist can also provide you with an at-home professional whitening kit that includes a custom tray that’s fitted to your teeth.

Other professional options for lightening craze lines, covering them, or changing the surface of your teeth include:

• filling the lines in with composite resin
• professional in-office teeth whitening
• veneers

Can you prevent craze lines?

Craze lines may be hard to prevent completely. However, if you have habits, such as nail biting or eating ice, stopping these can help.

If you grind your teeth at night, lifestyle changes that help you relax and unwind may help. Habits like meditation, daily walks, taking warm baths, and shutting off electronics at bedtime help some people. There are other things you can do yourself that may help reduce teeth grinding.

You can also talk to your dentist about getting a night guard.

Craze lines that are visible can be reduced in appearance or avoided by stopping the use of nicotine products and by eliminating your intake of dark-colored beverages. This will help to stop already visible craze lines from darkening.

The takeaway

Craze lines are hairline cracks in teeth. They don’t usually progress into deep cracks and are considered cosmetic in nature. However, they may lead to cavities in teeth if proper dental hygiene isn’t done.

If you’re troubled by the appearance of craze lines, at-home whitening or in-office dental procedures may help.